Pin tumbler lock

ABSTRACT

A pin tumbler lock that is substantially pick proof comprising a plug having an independent but limited motion rotational band or ring around it, for each pin way, a solid cylindrical sleeve about the bands or rings, pins extending through the sleeve, and an additional set of bands or rings about the sleeve corresponding to the pins. Each bottom pin is recessed to accommodate a key-contact ball, and there being a block in the bottom of the key-way to prevent access to the bands or rings, thus preventing any manipulation thereof. The plug and surrounding rings prevents access to the sleeve and its surrounding rings.

United States Patent [191 Genakis 1 May 27, 1975 PIN TUMBLER LOCK [22] Filed: Feb. 19, 1974 [21] Appl. No.: 443,328

FOREIGN PATENTS OR APPLICATIONS Germany 70/378 Primary Examiner-Robert L. Wolfe Attorney, Agent, or FirmCharles R. Fay

[57] ABSTRACT A pin tumbler lock that is substantially pick proof comprising a plug having an independent but limited motion rotational band or ring around it, for each pin way, a solid cylindrical sleeve about the bands or rings, pins extending through the sleeve. and an additional set of bands or rings about the sleeve corresponding to the pins. Each bottom pin is recessed to accommodate a key-contact ball, and there being a block in the bottom of the key-way to prevent access to the bands or rings, thus preventing any manipulation thereof. The plug and surrounding rings prevents access to the sleeve and its surrounding rings.

8 Claims, 11 Drawing Figures PATENlEmm-wzv ms 3,885,409

PATENTEDMAYQY I975 SHEET FIG 10 FIG3 PIC-Le:

PIN TUMBLER LOCK Attention is directed to copending application Ser. No. 345,33(),f1led Mar. 27. 1973 and now abandoned.

BACKGROUND OF THE INVENTION An attempt at designing a pick proof pin tumbler lock is shown in US. Pat. No. 1,989,327, but this has several deficiencies which the present invention cures. The patented lock is at times difficult to operate. especially after an attempted pick; the bands or rings on the plug are interengageable which can cause malfunction and difficulty of aligning the pin openings with the pins. These and other deficiencies of the prior art are overcome by the present invention. which also greatly increases the number of combinations.

SUMMARY OF THE INVENTION A cylinder or other enclosure has a plug and sleeve, the plug and sleeve each being surrounded with a series of bands or rings. The plug has a keyway and there are top and bottom pins in the pin ways, each bottom pin having a ball at its lower end for contact by a key, the keyway being blocked at the bottom disallowing access to all the bands or rings as well as the sleeve. The balls may be recessed into the ends of the bottom pins.

The top and bottom pins center the rings and sleeve, and the rings are rotational completely independently of each other but have limiting stops arranged in both the plug and the sleeve. Usually an attempt to pick the lock results in the rings being offset to a degree making the lock inoperable. The limited motion of the rings permits centering by the bottom and top pins upon application of the key in neutral position. The spaces between the plug and its rings, and the sleeve and its rings, is only in thousandths of an inch and they also perform functions as false shear points. When the false shear point presents itself, the upward movement of the bottom pins will strike the inside edges of the rings and further lifting is impossible. The bottom pins are made in multiples for master keying to carry out this function with regard to both sets of rings, those about the plug and those about the sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in front elevation of the plug and cylinder;

FIG. 2 is a longitudinal section therethrough;

FIG. 3 is a view in side elevation of the plug showing the rings about the sleeve in solid lines and the rings around the plug in dotted lines;

FIG. 4 is a rear view of the plug, the sleeve, and the rings;

FIG. 5 is a top view of the rings on the sleeve;

FIG. 6 is a front view of a sleeve band or ring;

FIG. 7 is a side view of a ring looking in the direction of arrow 7 in FIG. 6;

FIG. 8 is a sectional view on an enlarged scale illustrating the action of the lock;

FIG. 9 is a top plan view of the sleeve;

FIG. 10 is an end view thereof; and

FIG. 11 is a partial view of the sleeve looking in the direction of arrow 11 in FIG. 10.

PREFERRED EMBODIMENT OF THE INVENTION A cylinder or enclosure 10 contains a plug 12 having a keyway 14. The plug 12 may have the usual cam 16. The keyway is not open at the bottom at 18 but is solid or has a solid insert therein so that outside contact cannot be made with the bands or rings on the plug.

The plug has pin ways for receiving multiple bottom pins 21, 22, and 23 and top pins 34 which have various lengths as usual. Each of the bottom pins may be recessed at its lower end accommodating freely rotating balls 24. This not only sockets the balls but provides essentially longer pins than they would be were the pins cut square. This also maintains a precision pin setting relative to the shear points.

For each pin way in the plug there is a ring or band 26 encircling the plug. Each ring 26 has a hole 28 to receive a pin, see FIG. 8. Also each ring 26 has a circumferentially elongated slot or other aperture 30 receiving a limit pin 32 on the plug 12. The rings are completely independent of each other and can rotate on the plug as limited by the pins 32 and slots 30.

The rings 26 are surrounded by a solid cylindrical sleeve 36 closely fitting the same, and the sleeve has a series of apertures 38 that receive the bottom and top pin parts 21, 22, 23, and in some cases pins 34. The sleeve is surrounded by a series of independent bands or rings 40 which are equivalent to those at 26, there also being a ring 40 for each pin way. Each ring 40 has an aperture 42 receiving a limit pin 44 fixed in the sleeve 36. The provision of sleeve 36 and rings 40 very greatly increases the number of combinations openable by a series of keys, and also provides two shear points. Each ring 40 has an aperture 46 for the reception of the top and bottom pins 21, 22, and 23. Top pins 34 are spring pressed as usual normally locking the plug rings and the sleeve to the cylinder. The correct key or keys will raise the pins to the proper shear point, e.g., either one of the two shear points, so as to enable turning of the plug to unlock.

The disclosure of FIG. 8 shows a construction that can be operated either right or left, but shows the right hand operation. It also shows the action between the sleeve rings 40 and the cylinder; but of course this action is also possible between the plug rings 26 and the inner periphery of the sleeve. Thus master keying is provided for as well as a very large number of combinations, with different keys.

I claim:

1. A pin tumbler lock comprising an enclosure, a plug therein, a keyway in the plug, a set of pinways, a set of multiple part bottom pins in the pinways, a set of independently rotational rings on the plug, one ring for each pinway,

a solid cylindrical sleeve surrounding the plug rings, an aperture in the sleeve for each pinway, a set of independently rotational rings on the sleeve, one ring for each pinway.

an aperture in each ring for the respective pin, means limiting the rotational motion of each ring, and

a set of top and bottom pins in the enclosure and a plug for each pinway for interlocking the plug, rings, and sleeve to the cylinder.

2. The pin tumbler lock of claim I wherein the parts of the bottom pin are constructed and arranged for a correct key to lift the multiple bottom pins to unlock the plug while locking the sleeve and sleeve rings to the enclosure.

3. The pin tumbler lock of claim 2 wherein another key locks the plug to the sleeve and unlocks the sleeve and sleeve pins from the enclosure.

4 7. The pin tumbler lock of claim 1 wherein the keyway terminates short of the peripheral edge of the plug at the bottom of the keyway.

8. The pin tumbler lock of claim 1 wherein looseness between the plug and plug rings, between the plug rings and sleeve, and between the sleeve rings and enclosure completes a cycle for pick resistance or pick proofing. :u 1: 

1. A pin tumbler lock comprising an enclosure, a plug therein, a keyway in the plug, a set of pinways, a set of multiple part bottom pins in the pinways, a set of independently rotational rings on the plug, one ring for each pinway, a solid cylindrical sleeve surrounding the plug rings, an aperture in the sleeve for each pinway, a set of independently rotational rings on the sleeve, one ring for each pinway, an aperture in each ring for the respective pin, means limiting the rotational motion of each ring, and a set of top and bottom pins in the enclosure and a plug for each pinway for interlocking the plug, rings, and sleeve to the cylinder.
 2. The pin tumbler lock of claim 1 wherein the parts of the bottom pin are constructed and arranged for a correct key to lift the multiple bottom pins to unlock the plug while locking the sleeve and sleeve rings to the enclosure.
 3. The pin tumbler lock of claim 2 wherein another key locks the plug to the sleeve and unlocks the sleeve and sleeve pins from the enclosure.
 4. The pin tumbler lock of claim 1 wherein the means limiting the rotational motion of the rings on the plug comprises an aperture and a pin therein.
 5. The pin tumbler lock of claim 1 wherein the means limiting the rotational motion of the rings on the sleeve comprises an aperture and a pin therein, said pin and aperture being located on the sleeve and its rings.
 6. The pin tumbler lock of claim 1 wherein the plug and its rings prevent access to the sleeve and its rings.
 7. The pin tumbler lock of claim 1 wherein the keyway terminates short of the peripheral edge of the plug at the bottom of the keyway.
 8. The pin tumbler lock of claim 1 wherein looseness between the plug and plug rings, between the plug rings and sleeve, and between the sleeve rings and enclosure completes a cycle for pick resistance or pick proofing. 